For this reason, plain text emails you send are less likely to be viewed as dangerous or malicious by automated scanners because plain text simply can't be as dangerous as HTML. There can be no embedded tracking images and no hidden phishing URLs (because if the URL is visible in plain text, you'll be able to see the whole URL, rather than whatever text the sender wanted you to see). Plain text is more secure because nothing is hidden.
Virtually all of the mail you read will look at least a bit different if you read it in plain text, and some mail will be almost unreadable if it's been heavily formatted. The main drawback of plain text is that it has no formatting and no inline functionality like images or links.
Before we get into how to do this, it's worth noting that plain text has benefits and drawbacks, both for the sender and the receiver.
